One type of stationary cardiovascular exercise equipment which has become extremely popular based predominantly upon its low-impact and natural motion is the elliptical exercise machine. A wide variety of elliptical exercise machines have been developed. Briefly, elliptical exercise machines typically include foot support platforms supported upon foot links with the foot links pivotally connected at a first end through a linkage system to a drive shaft for travel along a defined closed loop path (e.g., circular, elliptical, oval, etc.) and connected at the other end for reciprocating motion along a defined path as the first end travels along the closed loop path. This combination of looping and reciprocating paths of travel at opposite ends of the foot links impart an “elliptical” type motion to the foot support platforms attached to the foot links.
U.S. Pat. No. 7,513,854 issued to Steams et al. discloses an elliptical exercise machine in FIGS. 10-18 and associated textual disclosure, the disclosure of which is hereby incorporated by reference, that includes a lateral displacement component to the typical parasagittal elliptical path of travel.
The elliptical exercise machine with lateral displacement disclosed in the '854 patent provides a unique gait that can enhance the exerciser's experience by providing a different exercise motion. However, the lateral movement produced by the elliptical exercise machine disclosed in the '854 patent tends to result in an undesired yaw of the foot pads (i.e., rotation of the foot pads about a vertical or yaw axis of the foot pad), such as depicted in FIGS. 12 and 16 in the '854 patent.
Hence, a substantial need exists for an elliptical exercise machine with foot pads capable of yaw controlled lateral glide as the foot pads travel along a closed loop.